#include<stdio.h>
#include<math.h>
#define NUM 320
int number[NUM];
int main(int argc, char const *argv[])
{
    int i,j,count=0;
    printf("There are following primes sequences in first row:\n");
    for(j=0,i=3;i<=1993;i+=2)
        if(fflag(i))
            number[j++]=i;
        for(j--;number[j]>1898;j--)
        {
            for(i=0;number[j]-number[i]>1898;i++);
            if(number[j]-number[i]==1898)
                printf("(%d).%3d,.....,%d\n",++count,number[i],number[j]);            
        }
    return 0;
}
int fflag(int i)
{
    int j;
    if(i<=1)
        return 0;
    if(i==2)
        return 1;
    if(!(i%2))
        return 0;
    for(j=3;j<=(int)(sqrt((double)i)+1);j+=2)
        if(!(i%j))
            return 0;
    return 1;
}
